JPWO2012147497A1 - Artificial vitreous material - Google Patents

Abstract

To provide an artificial vitreous material that has no toxicity to ocular tissues, can maintain a tamponade effect in the eye for a long time, and has excellent operability. The artificial vitreous material of the present invention contains a self-assembling peptide and a salt, and has an osmotic pressure of 40 mOsm / kg to 200 mOsm / kg. The artificial vitreous material of the present invention has no toxicity to the eye tissue, can maintain the tamponade effect for a long time in the eye, and is excellent in operability.

Description

  The present invention relates to an artificial vitreous material.

  The vitreous is a gel-like substance composed of collagen and sodium hyaluronate that fills the posterior cavity of the eyeball. The vitreous body has a tamponade effect that presses the retina from the inside of the eyeball and prevents its peeling. Therefore, it is an important tissue for the normal functioning of the eyeball. Currently, vitrectomy is widely applied for retinal vitreous diseases that require surgical treatment, but there is no appropriate substitute for vitreous, so the vitreous was removed even after vitrectomy. It remains. It has also been reported that after the vitreous body has been excised, the effect of intraocular drug administration by injection is lower than in the presence of the vitreous body.

  As the tamponade material after vitreous resection, gas (for example, air, expanded gas such as sulfur hexafluoride or propane fluoride), silicone oil, liquid perfluorocarbon, and the like are used. Among these, silicone oil is frequently used in clinical practice. However, silicone oil is highly toxic to ocular tissues and needs to be removed after a certain period of time, which is cumbersome to handle. Furthermore, the silicone oil may cause emulsification and cloudiness. Liquid perfluorocarbons are also used as temporary tamponade materials during surgery. However, liquid perfluorocarbons are also highly toxic to ocular tissues and are removed from the eye at the end of surgery. In the case of a gas tamponade using an expanding gas such as air, sulfur hexafluoride or propane fluoride, the effect is a short period of one day to one week due to absorption of gas in the eye (for example, Patent Document 1). ). In gas tamponade, the patient is usually forced to prone for about a week after surgery. Collagen, hyaluronic acid and salts thereof are also used as tamponade materials (for example, Patent Document 2). However, since these are derived from organisms and / or microorganisms, they are expensive and have not yet been applied to clinical applications.

  Further, as tamponade materials, compositions using polyethylene glycol modified at one end with a long-chain alkyl group and polyethylene glycol modified at both ends with a long-chain alkyl group have been proposed (for example, Patent Documents). 3). Although this composition is high in hardness and can be expected to have a tamponade effect, it is necessary to use a needle (21 gauge) that is thicker than a commonly used injection needle (25 gauge) in order to improve operability. Therefore, the load applied to the eyeball is increased, and the period required for treatment may be increased.

JP-A-6-154263 JP-A-5-184663 JP 2010-104632 A

  The present invention has been made to solve the above-mentioned problems, and its purpose is to have no toxicity to the eye tissue, to maintain the tamponade effect in the eye for a long time, and to be excellent in operability. It is to provide an artificial vitreous material.

According to the present invention, an artificial vitreous material is provided. The artificial vitreous material contains a self-assembling peptide and a salt, and has an osmotic pressure of 40 mOsm / kg to 200 mOsm / kg.
In a preferred embodiment, the artificial vitreous material includes 0.01 w / v% to 0.5 w / v% of the self-assembling peptide.
In a preferred embodiment, the self-assembling peptide consists of the following amino acid sequence:
Amino acid sequence: a ₁ b ₁ c ₁ b ₂ a ₂ b ₃ db ₄ a ₃ b ₅ c ₂ b ₆ a ₄
(In the amino acid sequence, a _{1 to} a ₄ are basic amino acid residues; b _{1 to} b ₆ are uncharged polar amino acid residues and / or hydrophobic amino acid residues, provided that at least 5 are hydrophobic amino acid residues; c ₁ and c ₂ are acidic amino acid residues; d is a hydrophobic amino acid residue).
In a preferred embodiment, in the above amino acid sequence, b ₁ ~b ₆ is an alanine residue independently, valine residue, leucine residue or isoleucine residue.
In a preferred embodiment, d is an alanine residue, valine residue, leucine residue, or isoleucine residue in the amino acid sequence.

  According to the artificial vitreous material of the present invention, the tamponade effect can be maintained in the eye for a long time. Moreover, since the artificial vitreous material of the present invention has appropriate fluidity, it is excellent in operability. The artificial vitreous material of the present invention contains a self-assembling peptide and a salt, and has no toxicity to ocular tissues. Therefore, according to the artificial vitreous material of the present invention, it is not necessary to maintain the prone state after surgery such as after tamponade by gas, and the extraction operation as in the case of using silicone oil or the like. Quality of life (QOL) can be improved. Moreover, since the artificial vitreous material of the present invention is excellent in drug retention, it is possible to prevent the effect of drug administration into the eye after removal of the vitreous body.

It is the photograph of the anterior eye part of the eyeball of a rabbit 1 week after inject | pouring the artificial vitreous material of this invention. It is a photograph of the fundus of the eyeball of a rabbit one week after injecting the artificial vitreous material of the present invention. It is the photograph of the retinal tissue which carried out HE staining of the rabbit 1 week after inject | pouring the artificial vitreous material of this invention. It is the photograph of the anterior eye part of the eyeball of a rabbit 1 month after inject | pouring the artificial vitreous material of this invention. It is a photograph of the fundus of the eyeball of a rabbit one month after injecting the artificial vitreous material of the present invention. It is the photograph of the retinal tissue which carried out HE staining of the rabbit 1 month after inject | pouring the artificial vitreous material of this invention. It is the photograph of the anterior eye part of the eyeball of a rabbit 3 months after inject | pouring the artificial vitreous material of this invention. It is the photograph of the fundus of the eyeball of a rabbit 3 months after injecting the artificial vitreous material of the present invention. It is the photograph of the retinal tissue which carried out HE staining of the rabbit 3 months after inject | pouring the artificial vitreous material of this invention.

<Definition of terms>
(1) In the present specification, “self-assembling peptide” refers to a peptide that spontaneously assembles in a solvent through interaction between peptide molecules. The interaction is not particularly limited, and examples thereof include a hydrogen bond, an ionic interaction, an electrostatic interaction such as van der Waals force, and a hydrophobic interaction. In one embodiment, self-assembling peptides can self-assemble to form nanofibers or gels in aqueous solutions at room temperature (eg, 0.4 w / v% aqueous peptide solution).
(2) In this specification, “gel” refers to a viscoelastic substance having both viscous and elastic properties.
(3) In the present specification, “hydrophilic amino acid” means basic amino acid such as arginine (Arg / R), lysine (Lys / K), histidine (His / H), aspartic acid (Asp / D), glutamic acid Acidic amino acids such as (Glu / E), tyrosine (Tyr / Y), serine (Ser / S), threonine (Thr / T), asparagine (Asn / N), glutamine (Gln / Q), cysteine (Cys / C) ) And other uncharged polar amino acids. The alphabets in parentheses are the three-letter code and single-character code for amino acids, respectively.
(4) In the present specification, “hydrophobic amino acid” means alanine (Ala / A), leucine (Leu / L), isoleucine (Ile / I), valine (Val / V), methionine (Met / M), Nonpolar amino acids such as phenylalanine (Phe / F), tryptophan (Trp / W), glycine (Gly / G) and proline (Pro / P) are included. The alphabets in parentheses are the three-letter code and single-character code for amino acids, respectively.

<Artificial vitreous material>
The artificial vitreous material of the present invention includes a self-assembling peptide and a salt. The artificial vitreous material of the present invention can maintain a long-term tamponade effect in the eye by including a self-assembling peptide and a salt, and is excellent in operability.

  The artificial vitreous material of the present invention has an osmotic pressure of 40 mOsm / kg to 200 mOsm / kg. When the osmotic pressure of the artificial vitreous material is within the above range, an artificial vitreous material that can maintain a longer-term tamponade effect in the eye and has excellent operability can be obtained. If the osmotic pressure exceeds 200 mOsm / kg, the transparency of the artificial vitreous material may be reduced. The osmotic pressure of the artificial vitreous material can be measured by an osmotic pressure measurement method (osmolarity measurement method) using a freezing point depression method according to the Japanese Pharmacopoeia.

  The artificial vitreous material of the present invention preferably has its pH adjusted to physiological conditions (about pH 7.4), and can be adjusted by using any pH adjusting agent, buffering agent, or the like.

A. Salt As the salt, a salt similar to the salt contained in a body fluid (for example, aqueous humor) is preferable, and any appropriate salt can be used. Examples of the salt include ionic salts such as sodium chloride and magnesium chloride. These salts may be used alone or in combination of two or more.

  The salt may be used in the form of a salt solution in which any salt is dissolved in any solvent. Distilled water etc. are mentioned as a solvent used for this salt solution. As the salt solution, a commercially available salt solution may be used. Specifically, diluting solutions for intraocular perfusates such as physiological saline, Ringer's solution, oxyglutathione solution (for example, diluting solution for oxyglutathione solution supplied by Nippon Alcon Co., Ltd. Manufactured by Co., Ltd., and trade name OPEAQUA (registered trademark) diluting solution for oxyglutathione solution). These salt solutions may be used alone or in combination of two or more.

  The ratio of the salt in the artificial vitreous material of the present invention can be adjusted so that the osmotic pressure of the obtained artificial vitreous material is 40 mOsm / kg to 200 mOsm / kg.

B. Self-assembling peptide The self-assembling peptide used in the present invention is not particularly limited as long as it is not toxic to a living body, particularly ocular tissue, and any appropriate self-assembling peptide can be used. The artificial vitreous material of the present invention preferably contains 0.01 w / v% to 0.5 w / v%, more preferably 0.05 w / v% to 0.4 w / v% of a self-assembling peptide. By including the self-assembling peptide within the above range, an artificial vitreous material that maintains a long-term tamponade effect in the eye and is excellent in operability can be obtained. Self-assembling peptides are also attracting attention as base materials for drug delivery systems. Therefore, the artificial vitreous material of the present invention can prevent a decrease in the effect of administering the drug injected into the eye after being injected into the eye. Only one type of self-assembling peptide may be used, or two or more types may be used in combination.

Preferably, the self-assembling peptide used in the present invention has the following amino acid sequence.
Amino acid sequence: a ₁ b ₁ c ₁ b ₂ a ₂ b ₃ db ₄ a ₃ b ₅ c ₂ b ₆ a ₄
(In the above amino acid sequence, a _{1 to} a ₄ represent basic amino acid residues; b _{1 to} b ₆ represent uncharged polar amino acid residues and / or hydrophobic amino acid residues, provided that at least 5 are hydrophobic amino acid residues; c ₁ and c ₂ represent acidic amino acid residues; d represents hydrophobic amino acid residues).
By using a self-assembling peptide consisting of the above amino acid sequence, a self-assembling peptide capable of maintaining a tamponade effect for a longer period in the eye can be obtained. Moreover, since the peptide which consists of the said amino acid sequence can form the gel excellent in transparency and mechanical strength on physiological conditions, it can be used suitably as an artificial vitreous material.

  The amino acid constituting the self-assembling peptide may be an L-amino acid or a D-amino acid. Moreover, a natural amino acid may be sufficient and a non-natural amino acid may be sufficient. Natural amino acids are preferred because they are available at low cost and facilitate peptide synthesis.

In the amino acid sequence, a _{1 to} a ₄ represent basic amino acid residues. The basic amino acid is preferably arginine, lysine or histidine, more preferably arginine or lysine. This is because these amino acids are strongly basic. a _{1 to} a ₄ may be the same amino acid residue or different amino acid residues.

In the amino acid sequence, b _{1 to} b ₆ represent uncharged polar amino acid residues and / or hydrophobic amino acid residues, and at least 5 of them are hydrophobic amino acid residues. The hydrophobic amino acid is preferably alanine, leucine, isoleucine, valine, methionine, phenylalanine, tryptophan, glycine or proline. The uncharged polar amino acid is preferably tyrosine, serine, threonine, asparagine, glutamine, or cysteine. This is because these amino acids are easily available.

Preferably, b ₃ and b ₄ are each independently any suitable hydrophobic amino acid residue, more preferably a leucine residue, an alanine residue, a valine residue, or an isoleucine residue, particularly preferably Is a leucine residue or an alanine residue. In the above amino acid sequence, when b ₃ and b ₄ positioned at the 6th and 8th positions are hydrophobic amino acid residues, the 3 amino acid residues at the 6th to 8th positions become the hydrophobic amino acid residues in succession. . Thus, the hydrophobic region formed at the center of the amino acid sequence can improve the strength of the artificial vitreous material due to its hydrophobic interaction, etc., and can maintain the tamponade effect in the eye for a long time. Presumed to be possible.

Preferably, b _{1 to} b ₆ are all hydrophobic amino acid residues. This is because the self-assembling peptide preferably forms a β-sheet structure and can self-assemble. More preferably, b _{1 to} b ₆ are each independently a leucine residue, an alanine residue, a valine residue, or an isoleucine residue, and more preferably a leucine residue or an alanine residue. In a preferred embodiment, 4 or more of b _{1 to} b ₆ are leucine residues, particularly preferably 5 or more of them are leucine residues, and most preferably all are leucine residues. It is easy to prepare artificial vitreous material because of its excellent solubility in water, and can improve the strength of the artificial vitreous material and maintain the tamponade effect in the eye for a long time. This is because a body material can be obtained.

In the amino acid sequence, c ₁ and c ₂ represent acidic amino acid residues. The acidic amino acid is preferably aspartic acid or glutamic acid. This is because these amino acids are easily available. c ₁ and c ₂ may be the same amino acid residue or different amino acid residues.

  In the amino acid sequence, d represents a hydrophobic amino acid residue. As described above, since d is a hydrophobic amino acid residue and has a predetermined symmetrical structure, an artificial vitreous material with better mechanical strength is obtained, and the tamponade effect is maintained in the eye for a long time. It will be possible to do this.

  d is preferably an alanine residue, a valine residue, a leucine residue, or an isoleucine residue. In this case, the side chain length of the amino acid on the hydrophilic surface side of the β sheet structure formed by the self-assembling peptide can be non-complementary, but the self-assembling peptide can exhibit excellent self-organizing ability, Furthermore, it is possible to obtain an artificial vitreous material that is superior in mechanical strength and can maintain the tamponade effect in the eye for a long period of time.

  The total charge in the neutral region of the amino acid residues contained in the self-assembling peptide is substantially +2. That is, the self-assembling peptide does not cancel out the positive charge and the negative charge derived from the side chain of the amino acid residue contained in the peptide in the neutral region. In addition, since the N-terminal and C-terminal amino acid residues are both basic amino acid residues, the self-assembling peptide used in the present invention is, for example, electrostatic in addition to electrostatic attraction between peptides. Since repulsive force works and these delicate balances are maintained, excessive association does not substantially occur, and it is assumed that a stable gel can be formed without precipitation in a neutral region close to physiological conditions. . In the present specification, the “neutral region” refers to a region having a pH of 6 to 8, and preferably a pH of 6.5 to 7.5.

  The charge of the self-assembling peptide at each pH can be calculated, for example, according to the method of Lehninger (Biochimie, 1979). The Rainer's method can be performed, for example, by a program available on the EMBL WWW Gateway to Isoelectric Point Service website (http://www.embl-heidelberg.de/cgi/pi-wrapper.pl).

Specific examples of preferable self-assembling peptides used in the present invention are shown below.
n-RLDLRLALRLLDLR-c (SEQ ID NO: 1)
n-RLDLRLLLLRLDLR-c (SEQ ID NO: 2)
n-RADLRLALRLLDLR-c (SEQ ID NO: 3)
n-RLDLRLALLRLDA-c (SEQ ID NO: 4)
n-RADLRLLLRLLDLR-c (SEQ ID NO: 5)
n-RADLRLLLRLDA-c (SEQ ID NO: 6)
n-RLDLRALLRLLDLR-c (SEQ ID NO: 7)
n-RLDLRLLARLDLR-c (SEQ ID NO: 8)

  The self-assembling peptide can be produced by any suitable production method. Examples thereof include a chemical synthesis method such as a solid phase method such as the Fmoc method or a liquid phase method, and a molecular biological method such as gene recombinant expression.

  The self-assembling peptide may be a self-assembling peptide that is arbitrarily modified (hereinafter referred to as a modified peptide). The modified peptide is a peptide obtained by subjecting the self-assembling peptide to any modification as long as it has a self-assembling ability and is not toxic to a living body, particularly an eye tissue. The site where the modification is performed may be the N-terminal amino group of the self-assembling peptide, the C-terminal carboxyl group, or both.

  As the modification, any appropriate modification can be selected as long as the obtained modified peptide has a self-organizing ability and is not toxic to a living body, particularly an eye tissue. For example, introduction of protecting groups such as N-terminal acetylation, C-terminal amidation; introduction of functional groups such as alkylation, esterification or halogenation; hydrogenation; monosaccharide, disaccharide, oligosaccharide, or polysaccharide And the like; introduction of a lipid compound such as fatty acid, phospholipid, or glycolipid; introduction of an amino acid or protein; introduction of DNA; introduction of a compound having other physiological activity. When an amino acid or protein is introduced, the peptide after introduction is a peptide in which any amino acid is added to the N-terminal and / or C-terminal of the self-assembling peptide. Included in modified peptides. Only one type of modification may be performed, or two or more types may be combined. For example, the N-terminus of an added peptide having a desired amino acid introduced at the C-terminus of the self-assembling peptide may be acetylated and the C-terminus amidated.

  The additional peptide (modified peptide) as a whole may not have the characteristics of the self-assembling peptide. Specifically, when an arbitrary amino acid is added and the sequence in the N-terminal direction and the sequence in the C-terminal direction are asymmetric about the 7-position hydrophobic amino acid sequence, the hydrophobic amino acid is equal to the hydrophilic amino acid. In some cases, it has a ratio. Even in such a case, since the self-assembling peptide has an extremely excellent self-assembling ability, the added peptide to which an arbitrary amino acid is added is also excellent in mechanical strength and is long-term in the eye. An artificial vitreous material capable of maintaining the tamponade effect can be obtained.

  When an amino acid or protein is introduced, the number of amino acid residues constituting the modified peptide after introduction is preferably 14 to 200, more preferably 14 to 100, still more preferably 14 to 50, Preferably it is 14-30, Most preferably, it is 14-20. If the number of amino acid residues exceeds 200, the self-assembling ability of the self-assembling peptide may be impaired.

  The type and position of the amino acid to be introduced can be appropriately set according to the use of the modified peptide. Preferably, hydrophobic amino acids and hydrophilic amino acids are introduced alternately from the N-terminal and / or C-terminal arginine residues (hydrophilic amino acids) of the self-assembling peptide.

  The modification can be performed by any appropriate method depending on the type and the like.

C. Additives The artificial vitreous material of the present invention may contain any additive in addition to the self-assembling peptide and salt. Examples of the additive include arbitrary drugs, for example, low molecular weight compounds, nucleic acids such as DNA and RNA, antibodies such as Lucentis, Avastin, and Macgen.

D. Method for Producing Artificial Vitreous Material The artificial vitreous material of the present invention can be produced by any suitable method. For example, an aqueous peptide solution is prepared by dissolving the self-assembled peptide in distilled water to a desired concentration, and the aqueous peptide solution, the salt, and optionally any additives and solvents are used with any stirring means. Thus, an artificial vitreous material can be obtained by stirring and mixing. As another method, for example, the artificial vitreous material can be obtained by stirring and mixing the peptide aqueous solution, the salt solution and, if necessary, any additive using any stirring means.

E. Method of Using Artificial Vitreous Material The artificial vitreous material of the present invention can be injected into the eyeball using any suitable means. For example, after filling the artificial vitreous material of the present invention into a syringe, it can be sterilized and injected into the eyeball using a syringe. Since the artificial vitreous material of the present invention is excellent in operability, even an injection needle that is thinner than a 25-gauge injection needle that is usually used for injection into the eyeball is easily injected into the eyeball. be able to.

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited by these Examples. The osmotic pressure of the artificial vitreous material was measured as follows.
(Measurement of osmotic pressure)
Each artificial vitreous material was diluted with distilled water (manufactured by Otsuka Pharmaceutical Factory, trade name: Pharmacopoeia Otsuka distilled water) until it became a solution state. Then, according to the osmotic pressure measuring method (osmolarity measuring method) described in the Japanese Pharmacopoeia, the diluted artificial vitreous material using an osmotic pressure measuring device (manufactured by Advanced Instruments, trade name: Osmometer 3900) The osmotic pressure of was measured. The osmotic pressure of each artificial vitreous material was obtained by proportionally calculating the obtained osmotic pressure with the dilution factor.

[Example 1]
Self-assembling peptide (Menicon Co., Ltd., trade name: PanaceaGel SPG-178, 1 w / v%) is mixed with distilled water (Otsuka Pharmaceutical Factory Co., Ltd., trade name: Pharmacopoeia Otsuka distilled water), and the peptide concentration is 0. A 15 w / v% aqueous peptide solution was obtained. The obtained aqueous peptide solution and salt solution 1 (manufactured by Showa Yakuhin Kako Co., Ltd., Opairqua (registered trademark) (oxyglutathione solution) dilution solution, osmotic pressure: 308 mOsm / kg) were mixed at a volume ratio of 2: 1 to produce artificial glass. Body material 1 was obtained. Table 1 shows the self-assembling peptide concentration, salt solution ratio and osmotic pressure in the obtained artificial vitreous material.

[Example 2]
Example except that salt solution 2 (manufactured by Nippon Alcon Co., Ltd., trade name: BSS Plus (registered trademark) (oxyglutathione solution), osmotic pressure: 308 mOsm / kg) was used instead of salt solution 1 In the same manner as in Example 1, an artificial vitreous material 2 was obtained. Table 1 shows the self-assembling peptide concentration, salt solution ratio and osmotic pressure in the obtained artificial vitreous material.

[Example 3]
An artificial vitreous material 3 was obtained in the same manner as in Example 2 except that the peptide concentration of the aqueous peptide solution was 0.45 w / v%. Table 1 shows the self-assembling peptide concentration, salt solution ratio and osmotic pressure in the obtained artificial vitreous material.

[Example 4]
An artificial vitreous material 4 was obtained in the same manner as in Example 1 except that the peptide concentration of the aqueous peptide solution was 0.075 w / v%. Table 1 shows the self-assembling peptide concentration, salt solution ratio and osmotic pressure in the obtained artificial vitreous material.

[Example 5]
Artificial vitreous material in the same manner as in Example 2, except that the peptide concentration of the aqueous peptide solution was 0.25 w / v%, and the mixing ratio of the aqueous peptide solution to the salt solution 1 was 2: 3 by volume. 5 was obtained. Table 1 shows the self-assembling peptide concentration, salt solution ratio and osmotic pressure in the obtained artificial vitreous material.

(Comparative Example 1)
A peptide aqueous solution with a peptide concentration of 1 w / v% was prepared in the same manner as in Example 1, and distilled water (manufactured by Otsuka Pharmaceutical Factory Co., Ltd., trade name: Pharmacopoeia Otsuka distilled water) was further added to the peptide aqueous solution to self-assemble. The peptide concentration was 0.1 w / v% to obtain an artificial vitreous material C1. Table 1 shows the self-assembling peptide concentration, salt solution ratio and osmotic pressure in the obtained artificial vitreous material.

(Comparative Example 2)
An artificial vitreous material C2 was obtained in the same manner as in Example 1 except that the peptide concentration of the aqueous peptide solution was 1 w / v%, and the mixing ratio of the aqueous peptide solution and the salt solution was 3: 7 by volume. . Table 1 shows the self-assembling peptide concentration, salt solution ratio and osmotic pressure in the obtained artificial vitreous material.

(Comparative Example 3)
Artificial vitreous material C3 in the same manner as in Example 1 except that the peptide concentration of the aqueous peptide solution was 0.2 w / v% and the mixing ratio of the aqueous peptide solution and the salt solution was 9: 1 by volume. Got. Table 1 shows the self-assembling peptide concentration, salt solution ratio and osmotic pressure in the obtained artificial vitreous material.

[Evaluation]
The artificial vitreous materials obtained in Examples 1 to 5 and Comparative Examples 1 to 3 were heated to 37 ° C. using an incubator (manufactured by SANYO, trade name: CO ₂ incubator), and the following evaluation was performed.
<Tamponade effect, physical properties and transparency>
The tamponade effect, physical properties and transparency of the warmed artificial vitreous material were visually confirmed and evaluated. The tamponade effect was evaluated as follows. The evaluation results are shown in Table 2.
Tamponade effect ◎: High tamponade effect
○: Has tamponade effect
×: No tamponade effect <operability>
The warmed artificial vitreous material was filled into a syringe (injection needle: 26 gauge), and the operability was evaluated by the feel (handling) at the time of injection. The evaluation results are shown in Table 2.

  The artificial vitreous material obtained in Examples 1 to 5 had a tamponade effect and was excellent in operability. Further, it has high transparency and can be suitably used as an artificial vitreous material. Usually, a 25 gauge needle is used for injection into the eyeball. The artificial vitreous material of the present invention was excellent in operability even when a thinner 26 gauge injection needle was used.

  The artificial vitreous material obtained in Comparative Example 1 and Comparative Example 3 was in a liquid state, and a sufficient tamponade effect was not obtained. On the other hand, although the artificial vitreous material obtained in Comparative Example 2 was excellent in the tamponade effect and operability, it was inferior in transparency and therefore not suitable for use as an artificial vitreous material.

[Test Example] Injection Test into Rabbit Eyeball 21 white rabbits weighing 2 kg were intramuscularly injected with ketamine 15 mg / kg and xylazine 10 mg / kg and subjected to deep anesthesia. It was confirmed that the corneal reflex was lost and the response to the pain stimulus had disappeared. Subsequently, vitrectomy for one eye was performed, and after excision, the artificial vitreous material 2 obtained in Example 2 was injected, and the operation was completed. As a surgical method, a three-port system (25G) method widely used in human clinical practice was used. After 1 day, 3 days, 1 week, 2 weeks, 3 weeks, 1 month, and 3 months, the eyeball into which the artificial vitreous material was injected was observed using a slit lamp microscope and a fundus microscope, and the retina An electrogram was measured. On each observation day, the eyeballs into which the artificial vitreous material was injected were removed from 3 rabbit specimens, stained with HE, and observed for the state of the retina. A photograph of the anterior segment of the eyeball one week after surgery is shown in FIG. 1a, a photograph of the fundus is shown in FIG. 1b, and a photograph of HE-stained retinal tissue is shown in FIG. 1c. Similarly, a photograph of the anterior segment of the eyeball one month after surgery is shown in FIG. 2a, a photograph of the fundus is shown in FIG. 2b, a photograph of HE-stained retinal tissue is shown in FIG. 2c, and a photograph of the anterior fundus of the eyeball 3 months after surgery. A photograph is shown in FIG. 3a, a photograph of the fundus is shown in FIG. 3b, and a photograph of HE-stained retinal tissue is shown in FIG. 3c.

  On all observation days, neither the lens nor the artificial vitreous material was cloudy, and the fundus could be observed. Even one month after the operation, no cataract occurred and no toxicity to the retinal tissue was observed. Furthermore, even after one month of surgery, the artificial vitreous material remained in the eyeball, and a good tamponade effect was maintained. Further, the artificial vitreous material itself remained without being cured or turbid. Even after 3 months of surgery, no cataract occurred and no toxicity to retinal tissue was observed. Furthermore, the artificial vitreous material was not cured or suspended, and a good tamponade effect was maintained. Thus, the artificial vitreous material of the present invention has excellent operability, and is not toxic to the eye tissue even after a long period of 3 months, and is a good tamponade in the eyeball. The effect could be maintained.

  The artificial vitreous material of the present invention can be suitably used as a tamponade material used after vitrectomy.

SEQ ID NO: 1 is a self-assembling peptide used in the present invention.
SEQ ID NO: 2 is a self-assembling peptide used in the present invention.
SEQ ID NO: 3 is a self-assembling peptide used in the present invention.
SEQ ID NO: 4 is a self-assembling peptide used in the present invention.
SEQ ID NO: 5 is a self-assembling peptide used in the present invention.
SEQ ID NO: 6 is a self-assembling peptide used in the present invention.
SEQ ID NO: 7 is a self-assembling peptide used in the present invention.
SEQ ID NO: 8 is a self-assembling peptide used in the present invention.

Claims (5)

An artificial vitreous material comprising a self-assembling peptide and a salt,
An artificial vitreous material having an osmotic pressure of 40 mOsm / kg to 200 mOsm / kg.   The artificial vitreous material according to claim 1, comprising 0.01 w / v% to 0.5 w / v% of the self-assembling peptide. The artificial vitreous material according to claim 1 or 2, wherein the self-assembling peptide has the following amino acid sequence:
Amino acid sequence: a ₁ b ₁ c ₁ b ₂ a ₂ b ₃ db ₄ a ₃ b ₅ c ₂ b ₆ a ₄
(In the amino acid sequence, a _{1 to} a ₄ are basic amino acid residues; b _{1 to} b ₆ are uncharged polar amino acid residues and / or hydrophobic amino acid residues, provided that at least 5 are hydrophobic amino acid residues; c ₁ and c ₂ are acidic amino acid residues; d is a hydrophobic amino acid residue). The artificial vitreous material according to claim 3, wherein b _{1 to} b ₆ are each independently an alanine residue, a valine residue, a leucine residue, or an isoleucine residue in the amino acid sequence.   The artificial vitreous material according to claim 3 or 4, wherein d is an alanine residue, a valine residue, a leucine residue, or an isoleucine residue in the amino acid sequence.